diff --git a/stio/lib/Makefile.am b/stio/lib/Makefile.am
index 8239fa3..898fd8d 100644
--- a/stio/lib/Makefile.am
+++ b/stio/lib/Makefile.am
@@ -36,7 +36,7 @@ libstio_la_SOURCES = \
 	stio-tmr.c
 libstio_la_CPPFLAGS = $(CPPFLAGS_LIB_COMMON)
 libstio_la_LDFLAGS = $(LDFLAGS_LIB_COMMON)
-libstio_la_LIBADD = $(LIBADD_LIB_COMMON)
+libstio_la_LIBADD = $(LIBADD_LIB_COMMON) $(SSL_LIBS)
 
 bin_PROGRAMS = stio
 stio_SOURCES = main.c
diff --git a/stio/lib/Makefile.in b/stio/lib/Makefile.in
index 178f532..0426766 100644
--- a/stio/lib/Makefile.in
+++ b/stio/lib/Makefile.in
@@ -102,7 +102,7 @@ am__installdirs = "$(DESTDIR)$(libdir)" "$(DESTDIR)$(bindir)" \
 LTLIBRARIES = $(lib_LTLIBRARIES)
 am__DEPENDENCIES_1 =
 am__DEPENDENCIES_2 = $(am__DEPENDENCIES_1)
-libstio_la_DEPENDENCIES = $(am__DEPENDENCIES_2)
+libstio_la_DEPENDENCIES = $(am__DEPENDENCIES_2) $(am__DEPENDENCIES_1)
 am_libstio_la_OBJECTS = libstio_la-stio.lo libstio_la-stio-pro.lo \
 	libstio_la-stio-sck.lo libstio_la-stio-tim.lo \
 	libstio_la-stio-tmr.lo
@@ -342,7 +342,7 @@ libstio_la_SOURCES = \
 
 libstio_la_CPPFLAGS = $(CPPFLAGS_LIB_COMMON)
 libstio_la_LDFLAGS = $(LDFLAGS_LIB_COMMON)
-libstio_la_LIBADD = $(LIBADD_LIB_COMMON)
+libstio_la_LIBADD = $(LIBADD_LIB_COMMON) $(SSL_LIBS)
 stio_SOURCES = main.c
 stio_CPPFLAGS = $(CPPFLAGS_LIB_COMMON)
 stio_LDFLAGS = $(LDFLAGS_LIB_COMMON)
diff --git a/stio/lib/main.c b/stio/lib/main.c
index 082221e..0aa6fcf 100644
--- a/stio/lib/main.c
+++ b/stio/lib/main.c
@@ -40,6 +40,17 @@
 #include <netpacket/packet.h>
 #include <net/if.h>
 
+#if defined(HAVE_OPENSSL_SSL_H) && defined(HAVE_SSL)
+#	include <openssl/ssl.h>
+#	if defined(HAVE_OPENSSL_ERR_H)
+#		include <openssl/err.h>
+#	endif
+#	if defined(HAVE_OPENSSL_ENGINE_H)
+#		include <openssl/engine.h>
+#	endif
+#	define USE_SSL
+#endif
+
 /* ========================================================================= */
 
 struct mmgr_stat_t
@@ -86,6 +97,22 @@ static stio_mmgr_t mmgr =
 
 /* ========================================================================= */
 
+#if defined(USE_SSL)
+static void cleanup_openssl ()
+{
+	/* ERR_remove_state() should be called for each thread if the application is thread */
+	ERR_remove_state (0);
+#if defined(HAVE_ENGINE_CLEANUP)
+	ENGINE_cleanup ();
+#endif
+	ERR_free_strings ();
+	EVP_cleanup ();
+#if defined(HAVE_CRYPTO_CLEANUP_ALL_EX_DATA)
+	CRYPTO_cleanup_all_ex_data ();
+#endif
+}
+#endif
+
 struct tcp_server_t
 {
 	int tally;
@@ -243,10 +270,11 @@ static void handle_signal (int sig)
 
 int main ()
 {
+	int i;
 
 	stio_t* stio;
 	stio_dev_sck_t* sck;
-	stio_dev_sck_t* tcp[2];
+	stio_dev_sck_t* tcp[3];
 
 	struct sigaction sigact;
 	stio_dev_sck_connect_t tcp_conn;
@@ -257,6 +285,11 @@ int main ()
 	stio_dev_sck_make_t sck_make;
 	tcp_server_t* ts;
 
+#if defined(USE_SSL)
+	SSL_load_error_strings ();
+	SSL_library_init ();
+#endif
+
 	stio = stio_open (&mmgr, 0, 512, STIO_NULL);
 	if (!stio)
 	{
@@ -322,10 +355,13 @@ int main ()
 		goto oops;
 	}
 
+	/* -------------------------------------------------------------- */
 	memset (&tcp_make, 0, STIO_SIZEOF(&tcp_make));
+	tcp_make.type = STIO_DEV_SCK_TCP4;
 	tcp_make.on_write = tcp_sck_on_write;
 	tcp_make.on_read = tcp_sck_on_read;
 
+
 	tcp[1] = stio_dev_sck_make (stio, STIO_SIZEOF(tcp_server_t), &tcp_make);
 	if (!tcp[1])
 	{
@@ -337,6 +373,45 @@ int main ()
 
 	memset (&tcp_bind, 0, STIO_SIZEOF(tcp_bind));
 	stio_sckadr_initforip4 (&tcp_bind.addr, 1234, STIO_NULL);
+	tcp_bind.options = STIO_DEV_SCK_BIND_REUSEADDR;
+
+	if (stio_dev_sck_bind (tcp[1],&tcp_bind) <= -1)
+	{
+		printf ("stio_dev_sck_bind() failed....\n");
+		goto oops;
+	}
+
+
+	tcp_lstn.backlogs = 100;
+	tcp_lstn.on_connect = tcp_sck_on_connect;
+	tcp_lstn.on_disconnect = tcp_sck_on_disconnect;
+	if (stio_dev_sck_listen (tcp[1], &tcp_lstn) <= -1)
+	{
+		printf ("stio_dev_sck_listen() failed....\n");
+		goto oops;
+	}
+
+
+	/* -------------------------------------------------------------- */
+	memset (&tcp_make, 0, STIO_SIZEOF(&tcp_make));
+	tcp_make.type = STIO_DEV_SCK_TCP4;
+	tcp_make.on_write = tcp_sck_on_write;
+	tcp_make.on_read = tcp_sck_on_read;
+
+	tcp[2] = stio_dev_sck_make (stio, STIO_SIZEOF(tcp_server_t), &tcp_make);
+	if (!tcp[2])
+	{
+		printf ("Cannot make tcp\n");
+		goto oops;
+	}
+	ts = (tcp_server_t*)(tcp[2] + 1);
+	ts->tally = 0;
+
+	memset (&tcp_bind, 0, STIO_SIZEOF(tcp_bind));
+	stio_sckadr_initforip4 (&tcp_bind.addr, 1235, STIO_NULL);
+	tcp_bind.options = STIO_DEV_SCK_BIND_REUSEADDR | STIO_DEV_SCK_BIND_SECURE;
+	tcp_bind.certfile = STIO_MT("stio.certfile");
+	tcp_bind.keyfile = STIO_MT("stio.keyfile");
 
 	if (stio_dev_sck_bind (tcp[1],&tcp_bind) <= -1)
 	{
@@ -400,6 +475,7 @@ int main ()
 #endif
 
 
+for (i = 0; i < 5; i++)
 {
 	stio_dev_pro_t* pro;
 	stio_dev_pro_make_t pro_make;
@@ -421,6 +497,7 @@ int main ()
 	}
 
 	stio_dev_pro_write (pro, "MY STIO LIBRARY\n", 16, STIO_NULL);
+//stio_dev_pro_killchild (pro); 
 //stio_dev_pro_close (pro, STIO_DEV_PRO_IN); 
 //stio_dev_pro_close (pro, STIO_DEV_PRO_OUT); 
 //stio_dev_pro_close (pro, STIO_DEV_PRO_ERR); 
@@ -430,11 +507,17 @@ int main ()
 
 	g_stio = STIO_NULL;
 	stio_close (stio);
+#if defined(USE_SSL)
+	cleanup_openssl ();
+#endif
 
 	return 0;
 
 oops:
 	g_stio = STIO_NULL;
 	stio_close (stio);
+#if defined(USE_SSL)
+	cleanup_openssl ();
+#endif
 	return -1;
 }
diff --git a/stio/lib/stio-pro.c b/stio/lib/stio-pro.c
index 0681077..516d8c9 100644
--- a/stio/lib/stio-pro.c
+++ b/stio/lib/stio-pro.c
@@ -610,11 +610,25 @@ static int dev_pro_ioctl (stio_dev_t* dev, int cmd, void* arg)
 				 * initiated by the slave device itself. */
 				stio_killdev (rdev->stio, (stio_dev_t*)rdev->slave[sid]);
 			}
-			break;
+			return 0;
 		}
-	}
 
-	return 0;
+		case STIO_DEV_PRO_KILL_CHILD:
+			if (rdev->child_pid >= 0)
+			{
+				if (kill (rdev->child_pid, SIGKILL) == -1)
+				{
+					rdev->stio->errnum = stio_syserrtoerrnum(errno);
+					return -1;
+				}
+			}
+
+			return 0;
+
+		default:
+			dev->stio->errnum = STIO_EINVAL;
+			return -1;
+	}
 }
 
 static stio_dev_mth_t dev_pro_methods = 
@@ -801,12 +815,16 @@ int stio_dev_pro_timedwrite (stio_dev_pro_t* dev, const void* data, stio_iolen_t
 	}
 }
 
-
 int stio_dev_pro_close (stio_dev_pro_t* dev, stio_dev_pro_sid_t sid)
 {
 	return stio_dev_ioctl ((stio_dev_t*)dev, STIO_DEV_PRO_CLOSE, &sid);
 }
 
+int stio_dev_pro_killchild (stio_dev_pro_t* dev)
+{
+	return stio_dev_ioctl ((stio_dev_t*)dev, STIO_DEV_PRO_KILL_CHILD, STIO_NULL);
+}
+
 #if 0
 stio_dev_pro_t* stio_dev_pro_getdev (stio_dev_pro_t* pro, stio_dev_pro_sid_t sid)
 {
diff --git a/stio/lib/stio-pro.h b/stio/lib/stio-pro.h
index 5c5a250..ca89c02 100644
--- a/stio/lib/stio-pro.h
+++ b/stio/lib/stio-pro.h
@@ -58,8 +58,6 @@ struct stio_dev_pro_t
 	stio_dev_pro_on_write_t on_write;
 	stio_dev_pro_on_close_t on_close;
 
-	stio_tmridx_t tmridx_connect;
-
 	stio_mchar_t* mcmd;
 };
 
@@ -115,7 +113,8 @@ struct stio_dev_pro_make_t
 
 enum stio_dev_pro_ioctl_cmd_t
 {
-	STIO_DEV_PRO_CLOSE
+	STIO_DEV_PRO_CLOSE,
+	STIO_DEV_PRO_KILL_CHILD
 };
 typedef enum stio_dev_pro_ioctl_cmd_t stio_dev_pro_ioctl_cmd_t;
 
@@ -153,6 +152,11 @@ STIO_EXPORT int stio_dev_pro_close (
 	stio_dev_pro_sid_t  sid
 );
 
+
+STIO_EXPORT int stio_dev_pro_killchild (
+	stio_dev_pro_t*     pro
+);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/stio/lib/stio-prv.h b/stio/lib/stio-prv.h
index 1a5abfb..6a23c5b 100644
--- a/stio/lib/stio-prv.h
+++ b/stio/lib/stio-prv.h
@@ -62,13 +62,13 @@ struct stio_t
 	{
 		stio_dev_t* head;
 		stio_dev_t* tail;
-	} dev; /* normal devices */
+	} actdev; /* active devices */
 
 	struct
 	{
 		stio_dev_t* head;
 		stio_dev_t* tail;
-	} hdev; /* halted devices */
+	} hltdev; /* halted devices */
 
 	struct
 	{
diff --git a/stio/lib/stio-sck.c b/stio/lib/stio-sck.c
index 2b874ec..f0ea330 100644
--- a/stio/lib/stio-sck.c
+++ b/stio/lib/stio-sck.c
@@ -37,6 +37,22 @@
 #include <arpa/inet.h>
 #include <netpacket/packet.h>
 
+#if defined(HAVE_OPENSSL_SSL_H) && defined(HAVE_SSL)
+#	include <openssl/ssl.h>
+#	if defined(HAVE_OPENSSL_ERR_H)
+#		include <openssl/err.h>
+#	endif
+#	if defined(HAVE_OPENSSL_ENGINE_H)
+#		include <openssl/engine.h>
+#	endif
+#	define USE_SSL
+#endif
+
+#if defined(USE_SSL)
+#	define HANDLE_TO_SSL(x) ((SSL*)(x))
+#	define SSL_TO_HANDLE(x) ((qse_httpd_hnd_t)(x))
+#endif
+
 /* ========================================================================= */
 void stio_closeasyncsck (stio_t* stio, stio_sckhnd_t sck)
 {
@@ -298,6 +314,14 @@ static int dev_sck_kill (stio_dev_t* dev, int force)
 		rdev->sck = STIO_SCKHND_INVALID;
 	}
 
+#if defined(USE_SSL)
+	if (rdev->secure_ctx)
+	{
+		SSL_CTX_free ((SSL_CTX*)rdev->secure_ctx);
+		rdev->secure_ctx = STIO_NULL;
+	}
+#endif
+
 	return 0;
 }
 
@@ -416,6 +440,9 @@ static int dev_sck_ioctl (stio_dev_t* dev, int cmd, void* arg)
 			stio_scklen_t sl;
 			stio_sckfam_t fam;
 			int x;
+		#if defined(USE_SSL)
+			SSL_CTX* ssl = STIO_NULL;
+		#endif
 
 			if (bnd->options & STIO_DEV_SCK_BIND_BROADCAST)
 			{
@@ -437,16 +464,49 @@ static int dev_sck_ioctl (stio_dev_t* dev, int cmd, void* arg)
 				}
 			}
 
+			if (bnd->options & STIO_DEV_SCK_BIND_SECURE)
+			{
+		#if defined(USE_SSL)
+				SSL_CTX* ssl;
+
+				ssl = SSL_CTX_new (SSLv23_server_method());
+				if (!ssl)
+				{
+					rdev->stio->errnum = STIO_ESYSERR;
+					return -1;
+				}
+
+				if (SSL_CTX_use_certificate_file (ssl, bnd->certfile, SSL_FILETYPE_PEM) == 0 ||
+				    SSL_CTX_use_PrivateKey_file (ssl, bnd->keyfile, SSL_FILETYPE_PEM) == 0 ||
+				    SSL_CTX_check_private_key (ssl) == 0)
+				{
+					rdev->stio->errnum = STIO_ESYSERR;
+					SSL_CTX_free (ssl);
+					return -1;
+				}
+
+				SSL_CTX_set_read_ahead (ssl, 0);
+		#else
+				rdev->stio->errnum = STIO_ENOIMPL;
+				return -1;
+		#endif
+			}
+
 			if (stio_getsckadrinfo (dev->stio, &bnd->addr, &sl, &fam) <= -1) return -1;
 
-			/* the socket is already non-blocking */
 			x = bind (rdev->sck, sa, sl);
 			if (x == -1)
 			{
 				rdev->stio->errnum = stio_syserrtoerrnum(errno);
+		#if defined(USE_SSL)
+				if (ssl) SSL_CTX_free (ssl);
+		#endif
 				return -1;
 			}
 
+		#if defined(USE_SSL)
+			rdev->secure_ctx = ssl;
+		#endif
 			return 0;
 		}
 
@@ -651,11 +711,7 @@ static int dev_evcb_sck_ready_stateful (stio_dev_t* dev, int events)
 					STIO_ASSERT (rdev->tmridx_connect == STIO_TMRIDX_INVALID);
 				}
 
-				if (rdev->on_connect (rdev) <= -1) 
-				{
-					printf ("ON_CONNECTE HANDLER RETURNEF FAILURE...\n");
-					return -1;
-				}
+				if (rdev->on_connect (rdev) <= -1) return -1;
 			}
 			else if (errcode == EINPROGRESS || errcode == EWOULDBLOCK)
 			{
diff --git a/stio/lib/stio-sck.h b/stio/lib/stio-sck.h
index f8538ff..fbf7b07 100644
--- a/stio/lib/stio-sck.h
+++ b/stio/lib/stio-sck.h
@@ -145,8 +145,10 @@ struct stio_dev_sck_make_t
 enum stio_dev_sck_bind_option_t
 {
 	STIO_DEV_SCK_BIND_BROADCAST = (1 << 0),
-	STIO_DEV_SCK_BIND_REUSEADDR = (1 << 1)
+	STIO_DEV_SCK_BIND_REUSEADDR = (1 << 1),
 /* TODO: more options --- TRANSPARENT...SO_RCVBUF, SO_SNDBUF, SO_RCVTIMEO, SO_SNDTIMEO, SO_KEEPALIVE */
+
+	STIO_DEV_SCK_BIND_SECURE    = (1 << 15)
 };
 typedef enum stio_dev_sck_bind_option_t stio_dev_sck_bind_option_t;
 
@@ -156,6 +158,9 @@ struct stio_dev_sck_bind_t
 	int options;
 	stio_sckadr_t addr;
 	/* TODO: add device name for BIND_TO_DEVICE */
+
+	const stio_mchar_t* certfile;
+	const stio_mchar_t* keyfile;
 };
 
 typedef struct stio_dev_sck_connect_t stio_dev_sck_connect_t;
@@ -189,6 +194,7 @@ struct stio_dev_sck_t
 
 	stio_dev_sck_type_t type;
 	stio_sckhnd_t sck;
+	void* secure_ctx;
 
 	stio_dev_sck_on_write_t on_write;
 	stio_dev_sck_on_read_t on_read;
@@ -241,7 +247,6 @@ STIO_EXPORT int stio_getsckadrinfo (
 );
 
 
-
 void stio_sckadr_initforip4 (
 	stio_sckadr_t* sckadr,
 	stio_uint16_t  port,
diff --git a/stio/lib/stio.c b/stio/lib/stio.c
index 21d8880..c705d3a 100644
--- a/stio/lib/stio.c
+++ b/stio/lib/stio.c
@@ -38,6 +38,21 @@
 static int schedule_kill_zombie_job (stio_dev_t* dev);
 static int kill_and_free_device (stio_dev_t* dev, int force);
 
+#define APPEND_DEVICE_TO_LIST(list,dev) do { \
+	if ((list)->tail) (list)->tail->dev_next = (dev); \
+	else (list)->head = (dev); \
+	(dev)->dev_prev = (list)->tail; \
+	(dev)->dev_next = STIO_NULL; \
+	(list)->tail = (dev); \
+} while(0)
+
+#define UNLINK_DEVICE_FROM_LIST(list,dev) do { \
+	if ((dev)->dev_prev) (dev)->dev_prev->dev_next = (dev)->dev_next; \
+	else (list)->head = (dev)->dev_next; \
+	if ((dev)->dev_next) (dev)->dev_next->dev_prev = (dev)->dev_prev; \
+	else (list)->tail = (dev)->dev_prev; \
+} while (0)
+
 stio_t* stio_open (stio_mmgr_t* mmgr, stio_size_t xtnsize, stio_size_t tmrcapa, stio_errnum_t* errnum)
 {
 	stio_t* stio;
@@ -96,39 +111,61 @@ int stio_init (stio_t* stio, stio_mmgr_t* mmgr, stio_size_t tmrcapa)
 
 void stio_fini (stio_t* stio)
 {
-	stio_dev_t* dev;
-
-	/* purge scheduled timer jobs and kill the timer */
-	stio_cleartmrjobs (stio);
-	STIO_MMGR_FREE (stio->mmgr, stio->tmr.jobs);
+	stio_dev_t* dev, * next_dev;
+	struct
+	{
+		stio_dev_t* head;
+		stio_dev_t* tail;
+	} diehard;
 
 	/* kill all registered devices */
-	while (stio->dev.head)
+	while (stio->actdev.head)
 	{
-		stio_killdev (stio, stio->dev.head);
+		stio_killdev (stio, stio->actdev.head);
 	}
 
-	while (stio->hdev.head)
+	while (stio->hltdev.head)
 	{
-		stio_killdev (stio, stio->hdev.head);
+		stio_killdev (stio, stio->hltdev.head);
 	}
 
 	/* clean up all zombie devices */
+	STIO_MEMSET (&diehard, 0, STIO_SIZEOF(diehard));
 	for (dev = stio->zmbdev.head; dev; )
 	{
 		kill_and_free_device (dev, 1);
-		if (stio->zmbdev.head == dev) dev = dev->dev_next;
+		if (stio->zmbdev.head == dev) 
+		{
+			/* the deive has not been freed. go on to the next one */
+			next_dev = dev->dev_next;
+
+			/* remove the device from the zombie device list */
+			UNLINK_DEVICE_FROM_LIST (&stio->zmbdev, dev);
+			dev->dev_capa &= ~STIO_DEV_CAPA_ZOMBIE;
+
+			/* put it to a private list for aborting */
+			APPEND_DEVICE_TO_LIST (&diehard, dev);
+
+			dev = next_dev;
+		}
 		else dev = stio->zmbdev.head;
 	}
 
-	while (stio->zmbdev.tail)
+	while (diehard.head)
 	{
 		/* if the kill method returns failure, it can leak some resource
 		 * because the device is freed regardless of the failure when 2 
 		 * is given to kill_and_free_device(). */
-		kill_and_free_device (stio->zmbdev.tail, 2);
+		dev = diehard.head;
+		STIO_ASSERT (!(dev->dev_capa & (STIO_DEV_CAPA_ACTIVE | STIO_DEV_CAPA_HALTED | STIO_DEV_CAPA_ZOMBIE)));
+		UNLINK_DEVICE_FROM_LIST (&diehard, dev);
+		kill_and_free_device (dev, 2);
 	}
 
+	/* purge scheduled timer jobs and kill the timer */
+	stio_cleartmrjobs (stio);
+	STIO_MMGR_FREE (stio->mmgr, stio->tmr.jobs);
+
 	/* close the multiplexer */
 	close (stio->mux);
 }
@@ -416,7 +453,7 @@ static STIO_INLINE int __exec (stio_t* stio)
 	int nentries, i;
 #endif
 
-	/*if (!stio->dev.head) return 0;*/
+	/*if (!stio->actdev.head) return 0;*/
 
 	/* execute the scheduled jobs before checking devices with the 
 	 * multiplexer. the scheduled jobs can safely destroy the devices */
@@ -460,12 +497,12 @@ static STIO_INLINE int __exec (stio_t* stio)
 	}
 
 	/* kill all halted devices */
-	while (stio->hdev.head) 
+	while (stio->hltdev.head) 
 	{
-printf ("KILLING HALTED DEVICE %p\n", stio->hdev.head);
-		stio_killdev (stio, stio->hdev.head);
+printf (">>>>>>>>>>>>>> KILLING HALTED DEVICE %p\n", stio->hltdev.head);
+		stio_killdev (stio, stio->hltdev.head);
 	}
-	STIO_ASSERT (stio->hdev.tail == STIO_NULL);
+	STIO_ASSERT (stio->hltdev.tail == STIO_NULL);
 
 #endif
 
@@ -490,14 +527,14 @@ void stio_stop (stio_t* stio)
 
 int stio_loop (stio_t* stio)
 {
-	if (!stio->dev.head) return 0;
+	if (!stio->actdev.head) return 0;
 
 	stio->stopreq = 0;
 	stio->renew_watch = 0;
 
 	if (stio_prologue (stio) <= -1) return -1;
 
-	while (!stio->stopreq && stio->dev.head)
+	while (!stio->stopreq && stio->actdev.head)
 	{
 		if (stio_exec (stio) <= -1) break;
 		/* you can do other things here */
@@ -563,11 +600,9 @@ stio_dev_t* stio_makedev (stio_t* stio, stio_size_t dev_size, stio_dev_mth_t* de
 	if (stio_dev_watch (dev, STIO_DEV_WATCH_START, 0) <= -1) goto oops_after_make;
 #endif
 
-	/* and place the new dev at the back */
-	if (stio->dev.tail) stio->dev.tail->dev_next = dev;
-	else stio->dev.head = dev;
-	dev->dev_prev = stio->dev.tail;
-	stio->dev.tail = dev;
+	/* and place the new device object at the back of the active device list */
+	APPEND_DEVICE_TO_LIST (&stio->actdev, dev);
+	dev->dev_capa |= STIO_DEV_CAPA_ACTIVE;
 
 	return dev;
 
@@ -607,6 +642,9 @@ static int kill_and_free_device (stio_dev_t* dev, int force)
 {
 	stio_t* stio;
 
+	STIO_ASSERT (!(dev->dev_capa & STIO_DEV_CAPA_ACTIVE));
+	STIO_ASSERT (!(dev->dev_capa & STIO_DEV_CAPA_HALTED));
+
 	stio = dev->stio;
 
 	if (dev->dev_mth->kill(dev, force) <= -1) 
@@ -615,14 +653,8 @@ static int kill_and_free_device (stio_dev_t* dev, int force)
 
 		if (!(dev->dev_capa & STIO_DEV_CAPA_ZOMBIE))
 		{
+			APPEND_DEVICE_TO_LIST (&stio->zmbdev, dev);
 			dev->dev_capa |= STIO_DEV_CAPA_ZOMBIE;
-
-			/* place it at the back of the zombie device list */
-			if (stio->hdev.tail) stio->hdev.tail->dev_next = dev;
-			else stio->zmbdev.head = dev;
-			dev->dev_prev = stio->hdev.tail;
-			dev->dev_next = STIO_NULL;
-			stio->zmbdev.tail = dev;
 		}
 
 		return -1;
@@ -632,15 +664,8 @@ free_device:
 	if (dev->dev_capa & STIO_DEV_CAPA_ZOMBIE)
 	{
 		/* detach it from the zombie device list */
-		if (dev->dev_prev)
-			dev->dev_prev->dev_next = dev->dev_next;
-		else
-			stio->zmbdev.head = dev->dev_next;
-
-		if (dev->dev_next)
-			dev->dev_next->dev_prev = dev->dev_prev;
-		else
-			stio->zmbdev.tail = dev->dev_prev;
+		UNLINK_DEVICE_FROM_LIST (&stio->zmbdev, dev);
+		dev->dev_capa &= ~STIO_DEV_CAPA_ZOMBIE;
 	}
 
 	STIO_MMGR_FREE (stio->mmgr, dev);
@@ -709,34 +734,18 @@ void stio_killdev (stio_t* stio, stio_dev_t* dev)
 		STIO_MMGR_FREE (stio->mmgr, q);
 	}
 
-	/* delink the dev object */
 	if (dev->dev_capa & STIO_DEV_CAPA_HALTED)
 	{
 		/* this device is in the halted state.
 		 * unlink it from the halted device list */
-		if (dev->dev_prev)
-			dev->dev_prev->dev_next = dev->dev_next;
-		else
-			stio->hdev.head = dev->dev_next;
-
-		if (dev->dev_next)
-			dev->dev_next->dev_prev = dev->dev_prev;
-		else
-			stio->hdev.tail = dev->dev_prev;
+		UNLINK_DEVICE_FROM_LIST (&stio->hltdev, dev);
+		dev->dev_capa &= ~STIO_DEV_CAPA_HALTED;
 	}
 	else
 	{
-		/* this device has not been halted.
-		 * unlink it from the normal active device list */
-		if (dev->dev_prev)
-			dev->dev_prev->dev_next = dev->dev_next;
-		else
-			stio->dev.head = dev->dev_next;
-
-		if (dev->dev_next)
-			dev->dev_next->dev_prev = dev->dev_prev;
-		else
-			stio->dev.tail = dev->dev_prev;
+		STIO_ASSERT (dev->dev_capa & STIO_DEV_CAPA_ACTIVE);
+		UNLINK_DEVICE_FROM_LIST (&stio->actdev, dev);
+		dev->dev_capa &= ~STIO_DEV_CAPA_ACTIVE;
 	}
 
 	stio_dev_watch (dev, STIO_DEV_WATCH_STOP, 0);
@@ -765,29 +774,18 @@ kill_device:
 
 void stio_dev_halt (stio_dev_t* dev)
 {
-	if (!(dev->dev_capa & (STIO_DEV_CAPA_HALTED | STIO_DEV_CAPA_ZOMBIE)))
+	if (dev->dev_capa & STIO_DEV_CAPA_ACTIVE)
 	{
 		stio_t* stio;
 
 		stio = dev->stio;
 
-		/* delink the dev object from the device list */
-		if (dev->dev_prev)
-			dev->dev_prev->dev_next = dev->dev_next;
-		else
-			stio->dev.head = dev->dev_next;
-		if (dev->dev_next)
-			dev->dev_next->dev_prev = dev->dev_prev;
-		else
-			stio->dev.tail = dev->dev_prev;
+		/* delink the device object from the active device list */
+		UNLINK_DEVICE_FROM_LIST (&stio->actdev, dev);
+		dev->dev_capa &= ~STIO_DEV_CAPA_ACTIVE;
 
 		/* place it at the back of the halted device list */
-		if (stio->hdev.tail) stio->hdev.tail->dev_next = dev;
-		else stio->hdev.head = dev;
-		dev->dev_prev = stio->hdev.tail;
-		dev->dev_next = STIO_NULL;
-		stio->hdev.tail = dev;
-
+		APPEND_DEVICE_TO_LIST (&stio->hltdev, dev);
 		dev->dev_capa |= STIO_DEV_CAPA_HALTED;
 	}
 }
@@ -826,6 +824,7 @@ int stio_dev_watch (stio_dev_t* dev, stio_dev_watch_cmd_t cmd, int events)
 			 * data for writing. */
 			events = STIO_DEV_EVENT_IN;
 			if (!STIO_WQ_ISEMPTY(&dev->wq)) events |= STIO_DEV_EVENT_OUT;
+			/* fall through */
 		case STIO_DEV_WATCH_UPDATE:
 			/* honor event watching requests as given by the caller */
 			epoll_op = EPOLL_CTL_MOD;
diff --git a/stio/lib/stio.h b/stio/lib/stio.h
index 3c93c8e..f7c7c1f 100644
--- a/stio/lib/stio.h
+++ b/stio/lib/stio.h
@@ -106,7 +106,6 @@ enum stio_errnum_t
 	STIO_ECONRS,     /* connection reset */
 	STIO_ENOCAPA,    /* no capability */
 	STIO_ETMOUT,     /* timed out */
-	
 
 	STIO_EDEVMAKE,
 	STIO_EDEVERR,
@@ -273,8 +272,9 @@ enum stio_dev_capa_t
 	STIO_DEV_CAPA_OUT_WATCHED  = (1 << 13),
 	STIO_DEV_CAPA_PRI_WATCHED  = (1 << 14), /**< can be set only if STIO_DEV_CAPA_IN_WATCHED is set */
 
-	STIO_DEV_CAPA_HALTED       = (1 << 15),
-	STIO_DEV_CAPA_ZOMBIE       = (1 << 16)
+	STIO_DEV_CAPA_ACTIVE       = (1 << 15),
+	STIO_DEV_CAPA_HALTED       = (1 << 16),
+	STIO_DEV_CAPA_ZOMBIE       = (1 << 17)
 };
 typedef enum stio_dev_capa_t stio_dev_capa_t;